Ventilating apparatus



9 v vvv J. F. BABBITT 3,036,509

VENTILATING APPARATUS 2 Sheets-Sheet l |l||| Illll Ill I III] Ill I 8 May 29, 1962 Filed May 25, 1960 zzvmvron. JOHN F. BABBrrT UE: SW 4! y 9, 1962 J. F. BABBlTT 3,036,509

VENTILATING APPARATUS Filed May 25, 1960 2 Sheets-Sheet 2 35 35 Fffi-I 3' "7 g? 6 INVENTOR. JOHN F. BABBITT "Au 6 S M 3,36,509 Patented May 29, 19 82 inc 3,036,509 VENTILATING APPARATUS John F. Babbitt, 190 Crescent Ave., Louisville, Ky. Filed May 23, 1960, Ser. No. 30,907 9 Claims. (Cl. 98-43) This invention relates to an improved and simplified apparatus for passing a gas from one space to another space, and, more particularly, to an apparatus useful for ventilating, air diffusing, or similar purposes in which motion is imparted to a body of air or gas.

An object of the invention is to provide a compact apparatus of reduced height for passing a gas from one space to another space.

Another object is to provide a compact apparatus for passing a gas from one space to another space by means of a power driven fan effecting a change in direction of flow of the gas between flow in one axial direction and flow in another axial direction during its movement through the apparatus.

A further object is to provide an improved and simplified fan blade construction for use in apparatus of the described type.

A still further object is to provide an improved arrangement of static structure for guiding the flow of gas from one space to another space.

Other objects and advantages of the invention will become more apparent as the description proceeds and when considered in conjunction with the accompanying drawings in which:

FIG. 1 is a top plan view of an assembled structure embodying the invention and with a four-bladed fan being shown in dotted lines;

FIG. 2 is a sectional view taken on line 22 of FIG. 1 and showing the assembled structure mounted upon a suitable base structure;

FIGS. 3, 4, S and 6 are sectional views to an enlarged scale of a fan blade taken on lines 3-3; 4-4; 5-5; and 66, respectively, of FIG. 2;

FIG. 7 is a view similar to that of FIG. 2 and showing a modified hood member and modified ends of the fan blade; and

FIG. 8 is an end view to an enlarged scale of the end of a fan blade as viewed along line S8 of FIG. 2.

In accordance with the invention there is provided a compact structure for guiding a gas moving between one space, such as the interior of a building, and another space, such as the exterior of the building, and for mounting a power driven fan which effects the movement of that gas. The structure includes an annular space through which the gas moves with an axial flow and a circular space, concentric with the annular space, and through which the gas moves with an axial flow. Positioned between the annular and circular spaces is a wall member having a concave outer surface which, in conjunction with the skirt of a hood member, serves to define the annular space and having a convex inner surface terminating at an edge defining the circular space. A special type of power-driven fan blade having portions movable in each of the annular and circular spaces effects the movement of the gas through the apparatus.

Referring now to FIGS. 1 and 2, the invention is illustrated as being embodied in a roof or wall-mounted ventilator and wherein such roof or wall, shown at 9, provides an apertured base structure to which the coinpact structure, now to be described, may be conveniently attached. As a significant feature, a wall member 11 is employed and whose circular upper edge 12 is gradually increased in diameter into a flat planar portion 13, thus providing a convex inner surface and a concave outer surface for that wall member. The wall member may be made of relatively light material such as a sheet of thin gauge aluminum. The planar portion 13 preferably forms the upper surface of a centrally apertured cap member 14. The cap member in turn is suitably mounted upon the base structure as by means of a flange 10 on that structure, so as to confine the gas passing from or into that base structure and to cause such gas to pass within the boundary defined by the convex surface of wall 11. The configuration of the cap member may vary depending upon the shape of the aperture in the base structure and is not necessarily square as shown herein. Moreover, the Wall 11 and cap member may be formed of two separate pieces of material suitably joined together without departing from the invention.

Extending across the apertures in each of the base structure, and the wall 11 of the cap member, are one or more support rods 15 and 16 rigidly attached at their respective ends to the inner surface of the cap member and providing a rigid support upon which a motor 17 for driving a fan may be mounted. Completing the static portion of the apparatus is a suitably shaped hood member having an outer generally planar central portion 18 merging into a circular peripheral skirt 19, the outermost edge 20 of which preferably forms a flange extending generally parallel to the upper surface of cap member 14. As a significant feature, the diameter of the skirt 19 is greater than the diameter of edge 12 of wall 11 and the flange 2t overlaps that edge 12 axially of the apparatus. By means of spacer bolts or the like, seen at 21, 22, 23 and 24, the hood is rigidly supported upon the cap member, thus forming the described structure into a unitary assembly which can be readily and easily attached to or detached from the base structure flange 10.

Cooperating with the described assembly is a fan attached to hub 30 driven by shaft 31 of motor 17 and having a first blade portion movable within the circular orifice space defined by wall 11 and a second blade portion movable within the annular space between that wall'.

and the skirt 1'9. The curvature of these blade portions is such that one edge of each such blade portion moves in a plane which intersects the upper part of wall 11 and the other edge of each such blade portion moves in a plane which does not intersect wall 11, the significance of which will later appear.

It will be appreciated that since the invention may be employed for ventilating structures, or for structures for diffusing or creating air currents in a room, or for other uses, (all herein comprehended in the term ventilating apparatus), the following description therefor is to be taken in an illustrative and not a limiting sense. Assuming that base structure 9 represents the roof of a building from which air is to be removed and wherein a low sil houette ventilator is desirable, the area of the annular space defined between wall 11 and skirt 19 will be somewhat larger than the circular orifice space defined by the wall 11. At the same time, the linear speed or distance travelled by the second blade portion 32 per unit of time is greater than that travelled by the first blade portion 33 per unit of time. The second and first blade portions each have leading and trailing edges 34, 35 and 36, 37, respectively, but between such edges the two blade portions have reversed curvature as noted by a comparison of FEGS. 3 and 4. The second blade portion, moreover, is formed integrally with the first blade portion and preferably in radial prolongation thereof, a twist being given to the blade in the region where the first and second blade portions join each other. This twist, when viewed in side elevation as seen in FIG. 2 forms a generally triangular space 38 and in carrying out the invention, the fan blade is so mounted that the upper edge 12 of wall 11 occupies a part of the space provided by that twist. The

thus described blade also includes a mounting portion 39 which may be without curvature, and ineffective to move the gas, and which joins the blade to the hub 30. While a single such blade may be used, it is preferred, for dynamic stability, to provide two such blades joined end to end at the connecting portions thereof, as seen in FIG. 2. When a larger capacity of the apparatus is desired, an additional number of such joined blades may be employed as further represented by the dotted blade lines in FIG. 1.

With the foregoing description in mind the illustrative apparatus provides for the following operation. As the fan is turned clockwise by the motor, as seen in FIG. 1, the first blade portions 33 pull air from within the base structure '9, pass it axially through the circular orifice space defined by edge 12 of the wall 11 and force it into a flattened plenum space 40 of low height under the planar portion 18 of the hood.

At the same time, the second blade portions 32 pull this air from the plenum space and force it along the concave outer surface of wall 11, thus directing it in an annular stream along a plane generally parallel with the plane of the base structure. As a result of the edge 12 of the wall 11 projecting into the twist space 38, no appreciable bypassing of the air takes place and substantially all of the air must move into the plenum space 40 before being removed from the apparatus. During this movement the direction of flow of such air changes from an initial axial flow in one direction to an axial flow in the opposite direction and is accomplished with a surprisingly small amount of turbulence or pressure build-up under the hood portion of the static structure.

Various advantageous features of the invention will now be apparent, among which may be mentioned the low overall height of the structure; the simple and inexpensive nature of the component parts; and the efiicient shielding of the interior of the structure from rain, dust and the like originating from external sources. The overall height, for example, may be reduced by reduction in the height of flange 10, but in general it is preferred to have the plane of the cap member 14 not less than about four inches above the plane of the base structure 9 so that in case the air being moved contains extraneous material, such material, during the phase of annular discharge, will not be forced against that base structure.

Moreover, various modifications of that described structure may be employed, one such modification being seen in FIG. 7. Here the hood member may include a central planar portion 18A merging into a circular peripheral skirt 19A inclined parallel to the bevelled ends of the second blade portions and having an outermost edge 20A forming a flange generally parallel to the upper surface of cap member 14. In this arrangement the extreme ends of blade portions 32 are cut along a downwardly directed inclined plane and move in a trajectory relatively close to the inner surface of the inclined skirt 19A. It has been found that when high resistances to movement of the air are expected, other factors remaining equal, the design having the bevelled ends of the blades gives a more efficient operation and without requiring any greater overall height of the structure.

As will be appreciated by those familiar with the art, the relative dimensions of the lengths and curvatures of the first and second blade portions, as well as the relative areas of the annular space and circular orifice space may be widely varied without departing from the spirit of the invention. For example, the motor 17 may be driven so as to rotate the fan blades in a direction opposite to that described, as when it is desired to pull air from outside the base structure and to move it into the interior thereof. Thus, an annular intake and an axial discharge may be employed, as well as the preferred axial intake and annular discharge.

Having thus described the invention and its attendant advantages, it is intended that the appended claims are to cover such changes and modifications of the described invention as come within the true spirit and scope of the same.

What is claimed is:

1. A ventilating apparatus for use with a stationary base structure having an aperture therein, a cap member attachable to said base structure in surrounding relation to the aperture thereof, said cap member having a wall terminating in a circular edge spaced from the plane of said base structure and defining a circular aperture in said cap member for communication with the aperture in said base structure, a hood member having an outer wall directed toward said cap member and of a greater diameter than the diameter of said circular edge of said cap member, said hood member having a generally planar central portion merging into said outer wall and providing a low overall height and with the peripheral edge of said outer wall being located in a plane nearer said cap member than the plane of said central portion, means supporting said hood member upon said cap member with the central portion of said hood member disposed adjacent and in spaced relation to the circular edge of the wall of said cap member thereby to form a plenum chamber within said hood member and an annular aperture between the respective walls of said hood and cap members communicating with the exterior of siad apparatus, fan means including a blade having a first portion movable across said circular aperture and a second portion movable across said annular aperture, said blade portions being shaped to effect the movement of gas with a sequential travel through each of said apertures, a motor for driving said fan means, and means supporting said motor and fan means in operative position with respect to the fixed portions of said apparatus.

2. Apparatus as defined in claim 1 wherein said fan means and said motor are supported upon said cap member thereby to form of said cap member and the elem nts supported thereby a unitary assembly suitable for attach ment to or detachment from said base structure.

3. A ventilating apparatus for use with a stationary base structure having an aperture therein, a cap member attachable to said base structure in surrounding relation to the aperture thereof, said cap member having a wall with a convex inner surface and a concave outer surface lengthwise thereof and terminating at a circular edge spaced from the plane of said base structure and defining a circular aperture in said cap member for communication with the aperture in said base structure, a hood member having an outer wall directed toward said cap member and of a greater diameter than the diameter of said circular edge of said cap member, said hood member having a generally planar central portion merging into said outer wall and providing a low overall height and with the peripheral edge of said outer wall being located in a plane nearer said cap member than the plane of said central portion, means supporting said hood member upon said cap member with the central portion of said hood member disposed adjacent and in spaced relation to the circular edge of the wall of said cap member thereby to form a plenum chamber within said hood member and an annular aperture between the outer wall of the hood member and the concave surface of the wall of said cap member and communicating with the exterior of said apparatus, fan means including a blade having a first portion movable across said circular aperture for moving gas along said convex surface and a second portion movable across said annular aperture for moving gas along said concave surface, said blade portions being shaped to effect the movement of said gas with a sequential travel through each of said apertures, a motor for driving said fan means, and means supporting said motor and fan means in operative position with respect to the fixed portions of said apparatus.

4. Apparatus as defined in claim 3 wherein said outer wall of said hood member extends in overlapping axial relation to said wall of said cap member.

5. Apparatus as defined in claim 4 wherein said outer wall of said hood member terminates in a peripheral flange extending generally parallel to the surface of said base structure.

6. Apparatus as defined in claim 4 wherein said outer wall of said hood member is inclined outwardly toward said base structure and the tip of said second blade portion is inclined generally parallel to the incline of said outer wall.

7. A ventilating apparatus for use with a stationary base structure having an aperture therein, a cap member attachable to said base structure in surrounding relation to the aperture thereof, said cap member having a wall terminating in a circular edge spaced from the plane of said base structure and defining a circular aperture in said cap member for communication with the aperture in said base structure, a hood member having an outer wall directed toward said cap member and of a greater diameter than the diameter of said circular edge of said cap member, said hood member having a generally planar central portion merging into said outer wall and with the peripheral edge of said outer wall being located in a plane nearer said cap member than the plane of said central portion, means supporting said hood member upon said cap member with the central portion of said hood member disposed adjacent and in spaced relation to the circular edge of the wall of said cap member thereby to form a flattened plenum chamber within said hood member and an annular aperture between the respective walls of said hood and cap members communicating with the exterior of said apparatus, fan means including a blade having a first blade portion movable across said circular aperture and joined to a second blade portion movable across said annular aperture, the junction of said blade portions being disposed closely adjacent the circular edge of said cap member wall whereby gas moved by said fan means through said apparatus is acted upon by said blade portions in sequence, said blade portions being shaped to efiect the movement of said gas with a sequential travel through each of said apertures, a motor for driving said fan means, and means supporting said motor and fan means in operative position with respect to the fixed portions of said apparatus.

8. Apparatus as defined in claim 7 wherein the effective leading edges of each of said blade portions lie to the same side of the radial axis of the blade of said fan.

9. Apparatus as defined in claim 7 wherein the shape of said blade portions includes an arcuate transverse configuration with the concave side thereof facing in the direction of rotational movement of said blade portions.

References Cited in the file of this patent UNITED STATES PATENTS 2,101,502 Keller Dec. 7, 1937 2,398,113 Parrish Apr. 9, 1946 2,900,892 Shepherd Aug. 25, 1959 FOREIGN PATENTS 157,507 Switzerland Dec. 16, 1932 971,613 France Jan. 19, 1951 

